To take this photo, I have tried a lot of position, and finally I almost laied on the ground. This photo was took in the spring, I want to express the vitality of the life in the new spring so I used the sun for setting against the flower.
In media, to emphasize the main topic, we have a great and effective way that finding an obeject for setting against the subject. In this way, we have two kind of object to choose, one is standing on the same side of the subject, the other one is standing on the opposite side.
Firstly, tlaking about the object that standing on the same side of the subject, we can use this object to set against the subect so that the meaning that we want the audience know of the suject can be stressed. For example, the photo I posted above, the subject is the flower and the sun is the object. The sun is shining and the sunshine is warm, that can be simplly used to let audience to understand the vitality of the life in the spring.
Then, regarding to the object that standing ont the opposite side of the subject, it is more easier to understand because we often see this in lots of classical and typical stories such as the Snos White, Agents of S.H.I.E.L.D and Cinderella. In these stories, there is a commen point that a kind and nice subject and a evil enemy. And also, the subject always win against the enemy. This is the contrast. The evil enemy always serces as a foil to the kind and righteous subject so that the main idea that justice and kindness win forever can be stressed.